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<FONT color="green">001</FONT>    package org.hackystat.telemetry.analyzer.function;<a name="line.1"></a>
<FONT color="green">002</FONT>    <a name="line.2"></a>
<FONT color="green">003</FONT>    import java.io.InputStream;<a name="line.3"></a>
<FONT color="green">004</FONT>    import java.util.TreeMap;<a name="line.4"></a>
<FONT color="green">005</FONT>    import java.util.logging.Logger;<a name="line.5"></a>
<FONT color="green">006</FONT>    <a name="line.6"></a>
<FONT color="green">007</FONT>    import javax.xml.bind.JAXBContext;<a name="line.7"></a>
<FONT color="green">008</FONT>    import javax.xml.bind.Unmarshaller;<a name="line.8"></a>
<FONT color="green">009</FONT>    <a name="line.9"></a>
<FONT color="green">010</FONT>    import org.hackystat.telemetry.analyzer.function.jaxb.FunctionDefinition;<a name="line.10"></a>
<FONT color="green">011</FONT>    import org.hackystat.telemetry.analyzer.function.jaxb.FunctionDefinitions;<a name="line.11"></a>
<FONT color="green">012</FONT>    import org.hackystat.telemetry.analyzer.model.TelemetryStreamCollection;<a name="line.12"></a>
<FONT color="green">013</FONT>    import org.hackystat.utilities.logger.HackystatLogger;<a name="line.13"></a>
<FONT color="green">014</FONT>    import org.hackystat.utilities.stacktrace.StackTrace;<a name="line.14"></a>
<FONT color="green">015</FONT>    <a name="line.15"></a>
<FONT color="green">016</FONT>    /**<a name="line.16"></a>
<FONT color="green">017</FONT>     * Implements a global singleton for managing telemetry function instances. It serves two purposes:<a name="line.17"></a>
<FONT color="green">018</FONT>     * &lt;ul&gt;<a name="line.18"></a>
<FONT color="green">019</FONT>     *   &lt;li&gt;Provides a central repository for all available telemetry functions.<a name="line.19"></a>
<FONT color="green">020</FONT>     *   &lt;li&gt;Provides a interface for invoking those functions.<a name="line.20"></a>
<FONT color="green">021</FONT>     * &lt;/ul&gt;<a name="line.21"></a>
<FONT color="green">022</FONT>     * <a name="line.22"></a>
<FONT color="green">023</FONT>     * All function names are case-insensitive.<a name="line.23"></a>
<FONT color="green">024</FONT>     * <a name="line.24"></a>
<FONT color="green">025</FONT>     * @author (Cedric) Qin ZHANG<a name="line.25"></a>
<FONT color="green">026</FONT>     */<a name="line.26"></a>
<FONT color="green">027</FONT>    public class TelemetryFunctionManager {<a name="line.27"></a>
<FONT color="green">028</FONT>    <a name="line.28"></a>
<FONT color="green">029</FONT>      /**<a name="line.29"></a>
<FONT color="green">030</FONT>       * Built-in functions for telemetry language and evaluator.<a name="line.30"></a>
<FONT color="green">031</FONT>       * Key is function name (lower case), value is TelemetryFunctionInfo instance. <a name="line.31"></a>
<FONT color="green">032</FONT>       */<a name="line.32"></a>
<FONT color="green">033</FONT>      private TreeMap&lt;String, TelemetryFunctionInfo&gt; functionMap = <a name="line.33"></a>
<FONT color="green">034</FONT>        new TreeMap&lt;String, TelemetryFunctionInfo&gt;();<a name="line.34"></a>
<FONT color="green">035</FONT>      <a name="line.35"></a>
<FONT color="green">036</FONT>      /** The global instance of this manager. */<a name="line.36"></a>
<FONT color="green">037</FONT>      private static TelemetryFunctionManager theInstance = new TelemetryFunctionManager();<a name="line.37"></a>
<FONT color="green">038</FONT>      <a name="line.38"></a>
<FONT color="green">039</FONT>      /**<a name="line.39"></a>
<FONT color="green">040</FONT>       * Gets the global instance.<a name="line.40"></a>
<FONT color="green">041</FONT>       * <a name="line.41"></a>
<FONT color="green">042</FONT>       * @return The global instance.<a name="line.42"></a>
<FONT color="green">043</FONT>       */<a name="line.43"></a>
<FONT color="green">044</FONT>      public static TelemetryFunctionManager getInstance() {<a name="line.44"></a>
<FONT color="green">045</FONT>        return theInstance;<a name="line.45"></a>
<FONT color="green">046</FONT>      }<a name="line.46"></a>
<FONT color="green">047</FONT>    <a name="line.47"></a>
<FONT color="green">048</FONT>      /**<a name="line.48"></a>
<FONT color="green">049</FONT>       * Defines "built-in" telemetry functions. <a name="line.49"></a>
<FONT color="green">050</FONT>       */<a name="line.50"></a>
<FONT color="green">051</FONT>      private TelemetryFunctionManager() {<a name="line.51"></a>
<FONT color="green">052</FONT>        Logger logger = HackystatLogger.getLogger("org.hackystat.telemetry");<a name="line.52"></a>
<FONT color="green">053</FONT>        FunctionDefinitions definitions = null;<a name="line.53"></a>
<FONT color="green">054</FONT>        <a name="line.54"></a>
<FONT color="green">055</FONT>        try {<a name="line.55"></a>
<FONT color="green">056</FONT>          logger.info("Loading built-in telemetry function definitions.");<a name="line.56"></a>
<FONT color="green">057</FONT>          //InputStream defStream = getClass().getResourceAsStream("impl/function.definitions.xml");<a name="line.57"></a>
<FONT color="green">058</FONT>          InputStream defStream = <a name="line.58"></a>
<FONT color="green">059</FONT>            TelemetryFunctionManager.class.getResourceAsStream("impl/function.definitions.xml");<a name="line.59"></a>
<FONT color="green">060</FONT>          JAXBContext jaxbContext = JAXBContext<a name="line.60"></a>
<FONT color="green">061</FONT>          .newInstance(org.hackystat.telemetry.analyzer.function.jaxb.ObjectFactory.class);<a name="line.61"></a>
<FONT color="green">062</FONT>          Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();<a name="line.62"></a>
<FONT color="green">063</FONT>          definitions = (FunctionDefinitions) unmarshaller.unmarshal(defStream);<a name="line.63"></a>
<FONT color="green">064</FONT>        } <a name="line.64"></a>
<FONT color="green">065</FONT>        catch (Exception e) {<a name="line.65"></a>
<FONT color="green">066</FONT>          logger.severe("Could not find built-in telemetry function definitions! " <a name="line.66"></a>
<FONT color="green">067</FONT>              + StackTrace.toString(e));<a name="line.67"></a>
<FONT color="green">068</FONT>          return;<a name="line.68"></a>
<FONT color="green">069</FONT>        }<a name="line.69"></a>
<FONT color="green">070</FONT>    <a name="line.70"></a>
<FONT color="green">071</FONT>        for (FunctionDefinition definition : definitions.getFunctionDefinition()) {<a name="line.71"></a>
<FONT color="green">072</FONT>          String name = definition.getName();<a name="line.72"></a>
<FONT color="green">073</FONT>          try {<a name="line.73"></a>
<FONT color="green">074</FONT>            logger.info("Defining built-in telemetry function " + name);<a name="line.74"></a>
<FONT color="green">075</FONT>            Class&lt;?&gt; clazz = Class.forName(definition.getClassName());<a name="line.75"></a>
<FONT color="green">076</FONT>            TelemetryFunction telemetryFunc = (TelemetryFunction) clazz.newInstance();<a name="line.76"></a>
<FONT color="green">077</FONT>            TelemetryFunctionInfo funcInfo =  new TelemetryFunctionInfo(telemetryFunc, definition);<a name="line.77"></a>
<FONT color="green">078</FONT>            this.functionMap.put(name.toLowerCase(), funcInfo);<a name="line.78"></a>
<FONT color="green">079</FONT>          }<a name="line.79"></a>
<FONT color="green">080</FONT>          catch (Exception classEx) {<a name="line.80"></a>
<FONT color="green">081</FONT>            logger.severe("Unable to define " <a name="line.81"></a>
<FONT color="green">082</FONT>                + definition.getClassName() + ". Entry ignored. " + classEx.getMessage());<a name="line.82"></a>
<FONT color="green">083</FONT>            continue;<a name="line.83"></a>
<FONT color="green">084</FONT>          }<a name="line.84"></a>
<FONT color="green">085</FONT>        }<a name="line.85"></a>
<FONT color="green">086</FONT>      }<a name="line.86"></a>
<FONT color="green">087</FONT>      <a name="line.87"></a>
<FONT color="green">088</FONT>      /**<a name="line.88"></a>
<FONT color="green">089</FONT>       * Determines whether a particular telemetry function is available.<a name="line.89"></a>
<FONT color="green">090</FONT>       * <a name="line.90"></a>
<FONT color="green">091</FONT>       * @param functionName Telemetry function name.<a name="line.91"></a>
<FONT color="green">092</FONT>       * @return True if the specified telemetry function is available.<a name="line.92"></a>
<FONT color="green">093</FONT>       */<a name="line.93"></a>
<FONT color="green">094</FONT>      public boolean isFunction(String functionName) {<a name="line.94"></a>
<FONT color="green">095</FONT>        return this.functionMap.containsKey(functionName.toLowerCase());<a name="line.95"></a>
<FONT color="green">096</FONT>      }<a name="line.96"></a>
<FONT color="green">097</FONT>    <a name="line.97"></a>
<FONT color="green">098</FONT>      /**<a name="line.98"></a>
<FONT color="green">099</FONT>       * Gets telemetry function information by name.<a name="line.99"></a>
<FONT color="green">100</FONT>       * <a name="line.100"></a>
<FONT color="green">101</FONT>       * @param functionName The name of the function.<a name="line.101"></a>
<FONT color="green">102</FONT>       * @return The telemetry function information, or null if the function is not defined.<a name="line.102"></a>
<FONT color="green">103</FONT>       */<a name="line.103"></a>
<FONT color="green">104</FONT>      public TelemetryFunctionInfo getFunctionInfo(String functionName) {<a name="line.104"></a>
<FONT color="green">105</FONT>        return this.functionMap.get(functionName.toLowerCase());<a name="line.105"></a>
<FONT color="green">106</FONT>      }<a name="line.106"></a>
<FONT color="green">107</FONT>      <a name="line.107"></a>
<FONT color="green">108</FONT>      /**<a name="line.108"></a>
<FONT color="green">109</FONT>       * Invokes telemetry function to perform computation.<a name="line.109"></a>
<FONT color="green">110</FONT>       * <a name="line.110"></a>
<FONT color="green">111</FONT>       * @param functionName The name of the telemetry function.<a name="line.111"></a>
<FONT color="green">112</FONT>       * @param parameters An array of objects of type either &lt;code&gt;String&lt;/code&gt;,<a name="line.112"></a>
<FONT color="green">113</FONT>       *        &lt;code&gt;Number&lt;/code&gt;, and/or &lt;code&gt;TelemetryStreamCollection&lt;/code&gt;. <a name="line.113"></a>
<FONT color="green">114</FONT>       * <a name="line.114"></a>
<FONT color="green">115</FONT>       * @return Either an instance of &lt;code&gt;Number&lt;/code&gt; or &lt;code&gt;TelemetryStreamCollection&lt;/code&gt;. <a name="line.115"></a>
<FONT color="green">116</FONT>       * <a name="line.116"></a>
<FONT color="green">117</FONT>       * @throws TelemetryFunctionException If anything is wrong.<a name="line.117"></a>
<FONT color="green">118</FONT>       */<a name="line.118"></a>
<FONT color="green">119</FONT>      public Object compute(String functionName, Object[] parameters) <a name="line.119"></a>
<FONT color="green">120</FONT>          throws TelemetryFunctionException {<a name="line.120"></a>
<FONT color="green">121</FONT>    <a name="line.121"></a>
<FONT color="green">122</FONT>        TelemetryFunctionInfo functionInfo = this.getFunctionInfo(functionName.toLowerCase());<a name="line.122"></a>
<FONT color="green">123</FONT>        if (functionInfo == null) {<a name="line.123"></a>
<FONT color="green">124</FONT>          throw new TelemetryFunctionException(<a name="line.124"></a>
<FONT color="green">125</FONT>              "Telemetry function " + functionName + " does not exist.");<a name="line.125"></a>
<FONT color="green">126</FONT>        }<a name="line.126"></a>
<FONT color="green">127</FONT>        <a name="line.127"></a>
<FONT color="green">128</FONT>        //check input types<a name="line.128"></a>
<FONT color="green">129</FONT>        for (int i = 0; i &lt; parameters.length; i++) {<a name="line.129"></a>
<FONT color="green">130</FONT>          Object object = parameters[i];<a name="line.130"></a>
<FONT color="green">131</FONT>          if (! (object instanceof String || object instanceof Number<a name="line.131"></a>
<FONT color="green">132</FONT>               || object instanceof TelemetryStreamCollection)) {<a name="line.132"></a>
<FONT color="green">133</FONT>            throw new TelemetryFunctionException("Telemetry function parameter should be of type "<a name="line.133"></a>
<FONT color="green">134</FONT>                + "either 'String', 'Number', and/or 'TelemetryStreamCollection'.");<a name="line.134"></a>
<FONT color="green">135</FONT>          }<a name="line.135"></a>
<FONT color="green">136</FONT>        }<a name="line.136"></a>
<FONT color="green">137</FONT>        //delegate computation<a name="line.137"></a>
<FONT color="green">138</FONT>        Object result = functionInfo.getFunction().compute(parameters);<a name="line.138"></a>
<FONT color="green">139</FONT>        //check output types<a name="line.139"></a>
<FONT color="green">140</FONT>        if (! (result instanceof Number || result instanceof TelemetryStreamCollection)) {<a name="line.140"></a>
<FONT color="green">141</FONT>          throw new TelemetryFunctionException("Telemetry function " + functionName <a name="line.141"></a>
<FONT color="green">142</FONT>              + " implementation error. It returns a result of unexpected type.");<a name="line.142"></a>
<FONT color="green">143</FONT>        }<a name="line.143"></a>
<FONT color="green">144</FONT>        return result;<a name="line.144"></a>
<FONT color="green">145</FONT>      }<a name="line.145"></a>
<FONT color="green">146</FONT>    }<a name="line.146"></a>




























































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